Speaker: Zhenyu Zhang, Oak Ridge National Lab & Univ. of Tennessee
Date & Time: April 20, 2006 - 12:00pm
Location: Room 260, Wright-Rieman Chemistry Laboratory
Inverse Design of Metallic and Magnetic Nanostructures via Multiscale Modeling
Laboratory for Surface Modification
Zhenyu Zhang, Oak Ridge National Lab & Univ. of Tennessee,
12:00noon, Room 260, Wright-Rieman Chemistry Laboratory
Multiscale modeling is gaining an increasingly important role in guiding the fabrication of artificially structured nanomaterials with atomic-scale precision and desirable physical properties. In this talk, a few recent examples will be presented to illustrate its predictive power in modern materials research. The modeling approaches range from electronic-scale calculations based on first principles to mesoscopic-scale continuum elasticity theory. Specific physical systems considered include: (a) fabrication of ordered magnetic atom wires on non-magnetic metal substrates; (b) quantum growth of atomically flat superconducting metal overlayers on semiconductor substrates; and (c) optimal dopant control in dilute magnetic semiconductors via "Subsurfactant Epitaxy". Emphasis will be made on the substantially improved structure-property relationships achieved through such synergetic efforts between theory and experiment, including in the last example the striking observation of magnetic ordering temperatures well above 300 K.